Oven door hinge



March 19, 1968 R. w. HARRINGTON 'ET AL 3,373,733

OVEN DOOR HINGE Filed Sept. 25, 1966 5 Sheets-Sheet 1 FIG. 2

INVENTORS ROBERT W. HARRINGTON WILLIAM C. COVEY BY GEORGE MAC ARTHUR JR.

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ATTORNEYS March 19, 1968 R. w. HARRINGTON ET AL 3,373,733

OVEN DOOR HINGE Filed Sept. 23, 1966 3 Sheets-Sheet 2 INVENTORS ROBERTW. HARRINGTON WILLIAM C. COVEY BY GEORGE MAC ARTHUR JR.

(WWW fl im m ATTORNEYS FIG. 4

March 19, 1968 Rw, HARRINGTON ET AL- 3,373,733

OVEN DOOR HINGE Filed Sept. 23, 1966 5 SheetsSheet 25 Z I Q I 2 LL] I UI I O. U) M I Z 2 I I d I (I I i I I INVENTORS M ANGLE OF DOOR POSITIONBY GEORGE MACARTHUR F|G.9 Co; and M ATTORNEYS 3,373,733 OVEN DOOR HINGERobert W. Harrington, William C. Covey, and- George McArthur, Jr.,Delaware, Ohio, assignors to Sunray Stove Company, Delaware, Ohio FiledSept. 23, 1966, Ser. No. 581,478 13 Claims. (Cl. 126191) ABSTRACT OF THEDISCLOSURE The invention disclosed in this application relates to anoven door hinge and, more particularly, to a hinge for a lift-ofi doorwherein the structure of the hinge permits of the obtaining of allspring forces from a single spring which reaches a valley point oftension at the lift'off point and wherein the spring tension and thespatial relationship among the hinge elements remain substantiallyconstant during removal and replacement of the door. The spring closingforce acting on the door at the broil position is opposed not only bygravity but also by a cam surface.

Background Doors of cooking ovens are usually quite heavy, and personsusing such doors can experience ditliculty and inconvenience,particularly if they are required to lift the full weight of the doorupon closing it. Many mechanisms have been devised to aid in the closingof oven doors, and most comprise springs which function to oppose theweight of the door. In this connection, Stoligrosz et al., in US. PatentNo. 3,072,117, and Mills in US. Patent No. 2,539,151 for example, havesuggested the use of torsion coil springs in oven door closuremechanisms.

Similarly, the practice has long existed to provide means which allowthe door to rest at a preselected equilibrium position between itscompletely open and completely closed position so that the door can beeasily maintained in a desired partially opened position. Theequilibrium position is herein denoted the broil position. Prior to ourinvention, the means for providing a broil stop usually consisted of anextra spring in the hinge mechanism to hold a roller against a cam. Thesurface of the cam generally had either a raised portion or anindentation. When an oven door which includes such a device is beingpushed toward its closed position, the roller rolls into the indentationor rides up on the raised portion. In this manner, the door comes to anequilibrium position where it will remain partially open until it ispushed farther to the fully closed position or until it is pulled backtoward the open position.

For one to be able to remove a door from the oven in some facile mannerhas long been recognized as a desirable convenience for the cleaning ofthe oven and for other purposes. Many doors; such as that described byReeves in US. 2,592,333; are subject to removal in any one of severalpositions. Many doors require the unfastening of a spring, or similarmanual procedure, before they can be removed.

Furthermore, many oven doors, when once removed from the oven, aredifficult to replace. They often require extensive manipulation toproperly position them on the oven, especially when the removal of thedoor has reatent 3,373,733 Patented Mar. 19, 1968 sulted in a changedtension in a spring or a changed spatial relationship among the elementsof the door and hinge. These manipulations have proven difficult for ahousewife, especially in those instances where she is required toperform them when holding the weight of the door.

Objects Therefore it is an object of our invention to provide animproved hinge for an oven door.

A further object of our invention is to provide a single torsion springinside an oven door to simultaneously provide all spring forcesnecessary.

A further object of our invention is to provide means which will alloweasy removal of the door in one selected position while preventing itsremoval in any other position.

A further object of our invention is to simplify the replacement of thedoor, when once removed, back onto the oven.

A further object of our invention is to provide a hinge mechanism whichwill allow the complete oven door and hinge mechanism to be assembledindependently of the main manufacturing assembly line.

It is a specific object of the invention to provide a hinge for an ovendoor which effects a valley point of spring tension at a broil stopposition, the door being removable from the oven at only such positionand under conditions of a constant spring tension and a constant spatialrelationship among hinge elements during removal and replacement of thedoor.

The foregoing and related objects can be attained in a hinge for thedoor of an oven for supporting said door as it is opened and closed, andfor supporting said door at a broil position intermediate the doorsfully open and fully closed positions, said oven having structures fixedthereto for engaging elements of said hinge; said hinge comprising: (1)pivot means upon which said door pivots as it opens and closes; (2) alink member provided with a cam follower, said cam follower beingmovably secured to said door for circular movement therewith, and forradial movement with respect to said pivot means; (3) a torsion springcooperative with said door via said link member, said spring adapted tobe under tension at all positions of said door, and said tension actingon said door in a direction toward said doors closed position; (4) a camfixed relative to said pivot means and operable when said door is insaid broil position; said cam being positioned to engage said camfollow'er when the door is being moved in a closing direction to saidbroil position; and operates in a manner to effect outward radialmovement of said cam follower as the door moves on through and past thebroil position; (5) an outstop arm extending from and fixed to the innerside of said door and adapted for sliding engagement with said ovenstructures when the door is being moved from non-broil positions (wheresaid structures obstruct the removal of said arm from said oven) to abroil position (where said arm can be lifted free of said structures);and (6) supporting means with a fixed position relative to said pivotmeans and said cam and adapted to removably engage said oven structures;whereby said door and hinge can be removed from and returned to saidoven at only said broil position and when said spring is at a valleypoint of tension, thus preventing a change in spring tension and achange in spatial relationship between said door, said cam follower,said supporting means, and said cam during such removal and return.

A feature of the hinge of the invention is a provision for (1) elementswhich are fixed relative to the door and which have a specificallydetermined permissible vertical translational movement relative tocertain oven structures at intermediate positions of the door as thedoor moves circularly in opening and closing; (2) elements which arefixed relative to said oven structures and require a specific verticaltranslational movement of the elements fixed relative to the door fordisengagement from said elements fixed relative to the oven structures;and (3) a co-acting spring mechanism which permits the maintenance ofthe spatial relationship among all such elements at the broil positionwhether said hinge and door are on or off the oven.

Another advantage of our invention is that no spring is located in thehot area around the oven liner. This increases the life of the springsused.

Further objects and features of the invention will be apparent from aconsideration of the following description taken together with theaccompanying drawings illustrating preferred embodiments of ourinvention.

In the drawings:

FIG. 1 is a diagrammatic representation of a range and oven whichincludes the door hinge of the invention;

FIG. 2 is a view in perspective of a hinge constructed according to ourinvention;

FIG. 3 is also a view in perspective of a hinge constructed according toour invention, FIG. 3 showing the back of the hinge shown in FIG. 2;

FIG. 4 is a plan view, partly in section, showing the preferred camfollower element of our hinge;

FIG. 5 is a diagrammatic View, in side elevation, of a portion of theoutstop arm of the invention in its position relative to a locating pinwhen the oven door is fully open;

FIG. 6 is a view similar to that of FIG. 5 except that the position ofthe outstop arm is shown when the oven door is fully closed;

FIG. 7 is a view similar to that of FIG. 5 except that the position ofthe outstop arm is shown when the oven door is in a positionintermediate its fully open and its broil positions;

FIG. 8 is a view similar to that of FIG. 5 except that the position ofthe outstop arm is shown when the oven door is in its broil position;and

FIG. 9 is a graph illustrating the dependence of spring tension on thedoor position.

Description Referring more particularly to the drawings, we show in FIG.1 door hinges indicated generally by 12, cooperating with an oven door14 positioned in the oven portion 16 of a stove or range 18. Hinges 12,one of which is shown in more detail in FIGS. 2 and 3, comprise a pivotrod 20 upon which the door 14 pivots as it is opened and closed. Thepivot rod 20 is secured to a supporting arm 22, the latter including twohook portions 24 and 26 and an upwardly-facing cam 28.

The supporting arm hook portions 24 and 26, as shown in FIG. 3, forexample, are hooked over vertically spaced locating pins 30 and 32 whichare secured to the oven wall just inside the door opening.

A torsion spring 34 is positioned around the pivot rod 20, one end ofthe spring 34 being secured to a sleeve 36 which can be secured to thepivot rod 20 by means of a set screw 38. The other end of the spring 34is secured to a spring link member 40 by inserting the end of the spring34 through a hole 42 in the link member 40, or in any suitable manner.

A hinge panel 44 is secured to the door 14 and is provided with asubstantially circular hole 46 near its bottom end, the pivot rod 20being positioned for rotation of the hole 46 for pivotal motion of thepanel 44 about the rod 20.

The hinge panel 44 is also provided with a slot 48 through which isinserted a bolt 50, the latter securing the upper end of the spring linkmember 40 for simultaneous movement therewith.

An outstop arm 52 extends outwardly from the panel 44 (but inwardly withrespect to the oven 16). The outstop arm 52 has an upturned hook portion54 at its end which is adapted to hook onto the upper pin 30 when thedoor is in its fully open position (see FIG. 5). The outstop arm 52, asshown, has a unique shape, the upper and lower arcs, defining the upperand lower edges thereof, being shaped such that as the door 14 is openedor closed there is a change in the distance (indicated by the distance Xin FIGS. 7 and 8) between the upper edge of the outstop arm 52 and theupper pin 30. The distance X is the distance the outstop arm 52 can belifted in vertical translational movement without being obstructed bythe upper locating pin 30. The distance Y represents the distance whichthe hook 24 must be raised over the pin 30 to effect its clearance whenthe door is being removed. At all positions of the door, except at thedoors broil position, the distance X is smaller than the distance Y (seeFIGS. 5, 6, and 7) and the outstop arm 52 cannot be raised high enoughto permit clearance of the hook 24 over the pin 30 or clearance of thehook 26 over the pin 32. Actually, at the doors fully open position(FIG. 5) and at the doors fully closed position (FIG. 6), the distance Xis substantially zero. At the doors broil position, however, thedistance X is greater than the distance Y and the outstop arm 52 can belifted vertically high enough to permit the hooks 24 and 26 to cleartheir respective locating pins 30 and 32.

FIGURE 4 shows the preferred cam follower. Other types, includingnon-rolling types, could be used. As shown in FIG. 4, a roller 56 issecured to bolt 50 which is inserted through slot 48 in panel 44. A nut50a is provided for bolt 50. A rivet may be used instead of a bolt. Theroller 56 is adapted to ride on the cam 28 as the door 14 passes throughand past its broil position in a closing direction. A flange (or nut) 58on the bolt 50 se4rves to hold the roller 56 in position against thepanel 4 It may be noted that door 14, outstop arm 52, supporting arm 22,cam 28, and pivot rod 20 are all fixed relative to each other insofar asvertical translational movement is concerned, although the elements 14and 52 may rotate relative to elements 22 and 28.

Operation When the door 1 4 is first positioned on the oven 16,- asuitable tension is placed on the torsion spring 34 by rotating thesleeve 36. A suitable tension is one which nearly oifsets the weight ofthe door at the fully open position and which can force the door to itsbroil position from an intermediate position between the broil positionand the fully open position. This tension, as will appear hereinafter,will not cause roller 56 to ride up cam 28.

When a desired tension is attained, the sleeve 36 is secured to thepivot rod 20 by means of the set screw 38.

If the door is fully open, as shown in FIG. 1, the gravity pull orweight of the door overbalances the tension of the spring and releasablyholds the door open at the same time, the book 54 of outstop arm 52 ishooked on the upper locating pin 30 (FIG. 5) and the bolt 50, withroller 56, is at the bottom of the slot 48, the bottom of the slot beingthe end toward the pivot rod 20. As the door moves from its fully openposition toward the broil position, tension on the spring 34 reduces,bolt 50 remains at the bottom of the slot 48, and outstop arm 52 ridesinwardly between locating pins 30 and 32, resting on lower pin 32.

When, during the closing of the door 14, the roller 56 engages the cam28, the bolt 50 is moved in the slot 48 radially outwardly with respectto the pivot rod 20. This latter motion pulls the spring link member 40radially outwardly and thus tightens the springs 34. In this manner,spring tension, which had been decreasing during the closing of thedoor, starts to increase at the broil position; that is, when the roller56 starts to ride up the cam 28. Thus, the spring tension has a valleypoint of tension at the broil position and the spring resists any effortto displace the door from this position toward the closed position. So,the door is releasably held in the broil position.

As the door continues to be closed, after it has passed the broilposition, the roller rides down the rear of the cam (toward the position49), the bolt 50 returns to the bottom end of the slot 48, the springlink member 40 moves radially inwardly, and the tension on the springagain reduces progressively. However, when the door is fully closed, thegravity pull is reduced to zero and the residual tension of the springis suflicient to hold the door releasably in the closed position.

When the door is opened from its fully closed position, the foregoingevents occur in reverse; the spring tension first increasing, then whenthe roller rides down the front of the cam 28, decreasing to a valleypoint of tension; and then when the roller no longer engages the cam,again increasing progressively until the door is fully open.

The operation is graphically illustrated in FIGURE 9. The vertical asisrepresents relative spring tension and the horizontal axis representsthe door angle between the fully open and the fully closed position. Thevalley point of spring tension is denoted as VP. Movement of the door ineither direction from the valley point will require the application offorce by the consumer.

As pointed out above; door 14, outstop arm 52, supporting arm 22, cam28, and pivot rod are fixed relative to each other insofar as verticaltranslational movement is concerned. Therefore, to remove the door andhinge assembly, it is necessary to raise the hooks 24 and 26 vertically(the distance Y of FIGS. 6, 7, and 8) to clear the locating pins and 32and, therefore, it is necessary to raise the outstop arm 52 verticallyan equal distance. The extent of vertical translational movementpermitted the outstop arm 52 depends on the distance (distance X ofFIGS. 7 and 8) between its top edge and the upper locating pin 30. Asshown in FIG. 8, the distance X is greater than the distance Y at thebroil position but at no other position of the door (see FIGS. 5, 6, and7).

Thus at the broil position, the door and hinge assembly is raisedvertically until hooks 24 and 26 clear pins 30 and 32. The assembly isthen moved horizontally away from the oven. To replace the door, thedoor and hinge assembly are repositioned by setting the bottom edge ofthe outstop arm 52 on the lower pin 32 and, while holding the door at anangle more nearly vertical than the broil position, pushing the assemblyhorizontally inward until the hooks 24 and 26 pass over the pins 30 and32. The assembly is then moved vertically downward to its originalposition.

While the door is being removed and replaced there is no change intension on the spring and no change in the spatial relationship of thedoor and hinge elements. Therefore, no adjustment of the spring or anyof the hinge elements is required during the removal of the door. Thislatter advantage is secured 'because of the fact that the door and hingeassembly is removed while the spring is at a tension valley point. If,on removal of the door, the hinge would tend to collapse; that is, causeit to act as if closing; this tendency would be offset by therequirement for energy to move the roller56 up the cam 28. If, to thecontrary, the hinge would tend to spread; that is, cause it to act as ifopening; this tendency would be offset by the requirement for energy toincrease tension on the spring. Therefore, the spring tension remains atequi- 6 librium and constant and the spatial relationship of the doorand hinge elements remains constant.

Because the manipulation required to attach the door to the range is sosimple, because it is unnecessary to attach any springs to the range,and because no screws or other fasteners are needed to attach the door,the whole door assembly, including the hinge mechanism, may bemanufactured independently of the main manufacturing assembly line. Thedoor is merely inserted into the range at the end of the assembly line.A stock of such door assemblies may be manufactured prior to the timeintended for their use.

Although not illustrated and not necessary to the opera- 4 tion of ourinvention, we have found it desirable to attach a retaining panel to thehinge panel 44. The retaining panel is fixed relative to the hinge panel44 and is positioned so that the supporting arm 22 may pass, in itsusual circular motion, between the hinge panel 44 and the retainingpanel. The space through which the supporting arm 22 passes is no largerthan required to allow this motion. The retaining panel thus preventsany possible separation of binge panel 44 from supporting arm 22 andassures that the cam will engage the cam follower when so desired.

It is to be understood that the detailed drawings and specific examplesgiven describe preferred embodiments of our invention and are forpurposes of illustration only, that the apparatus of the invention isnot limited to the precise details and precise conditions disclosed, andthat various changes may be made therein without departing from thespirit of the invention which is defined by the following claims.

We claim:

1. A hinge for the door of an oven for supporting said door as it isopened and closed, and for supporting said door at a broil positionintermediate the doors fully open and fully closed position, said ovenhaving structures fixed thereto for engaging elements of said hinge;said hinge comprising:

' (1) pivot means upon which said door pivots as it opens and closes;

(2) a link rnem ber provided with a cam follower, said cam followerbeing movably secured to said door for circular movement therewith, andfor radial movement with respect to said pivot means;

(3) a torsion spring cooperative with said door via said link member,said spring adapted to be under tension at all positions of said door,and said tension acting on said door in a direction toward said doorsclosed position;

(4) a cam fixed relative to said pivot means being operable when saiddoor is passing through said broil position, and being positioned toengage, when said door is closing, said cam follower at said broilposition in a manner to effect radial movement of said calm follower;

(5) an outstop arm extending from and fixed to the inner side of saiddoor and adapted for sliding engagement with said oven structures whenthe door is being moved from non-lbroil positions, where said structuresobstruct the rem-oval of said arm from said oven, to a broil position,Where said arm can be lifted free of said structures; and

(6) supporting means with a fixed position relative to said pivot meansand said cam and adapted to removably enga'ge said oven structures;

whereby said door and hinge can be removed from and returned to saidoven at only said broil position and when said spring is near a valleypoint of tension, thus preventing a change in spring tension and achange in spatial relationship between said door, said cam follower,said supporting means, and said cam during such removal and return.

2. The hinge according to claim 1 wherein said support ing means is asup-porting arm fixed to and extend-ing from said pivot means, said armbeing provided with hook elements for engaging said oven structure;whereby the vertical translational movement of said supporting arm andhook elements is limited to the extent of simultaneous verticaltranslational movement of said pivot means, said door, and said outstoparm' 3. The hinge according to claim 2 wherein the extent of verticaltranslational movement of said outstop arm permitted by said obstructingstructures is, in only said broil position, sufficient to effect thelifting of said hook elements free of said structures.

4. The hinge according to claim 1 wherein said pivot means is a rod andwherein said torsion spring is wrapped around said rod.

5. The hinge according to claim 1 wherein said supporting means, saidcam, and said pivot means form a unitary rigid structure.

6. The hinge according to claim 1 wherein said link member comprises aportion which is slidedly engaged in a longitudinal slot in a hingepanel of said door so that engagement of said cam follower with saidcam, upon the closing of said door, results in an outward radialmovement of said portion in said slot.

7. The hinge according to claim 1 wherein said cam follower is a roller.

8. A hinge for the door of an oven for supporting said door as it isopened and closed; for supporting said door at a :broil positionintermediate the doors fully open and fully closed positions; and forcooperation with upper and lower vertically spaced locating pins fixedlysecured to said oven; said hinge comprising:

(1) a rod pivotally secured to said door and upon which said door pivotsas it is opened and closed;

(2) a torsion spring wrapped around said rod and adapted to be undertension at all positions of said door, said tension acting on said doorin a direction toward said doors closed position;

(3) a tension link member secured to said spring;

(4) a roller forming a portion of said link member, said roller beingsecured to said door for circular movement therewith, for radialmovement relative to said pivot rod, and for rotational movement aboutits own axis;

(5) a supporting arm fixed to and extending from said pivot rod, saidsupporting arm being provided with spaced hook elements adapted to hookover and rest on said pins, and said supporting arm provided with anupwardly facing cam adapted to engage said roller when said door is inits broil position to effect, as said door is closing, an outward radialmovement of said roller and thus to effect a change from decreasingtension to increasing tension on said spring; and

(6) an outstop arm fixed to and extending from the inner side of saiddoor, said outstoparm adapted to move slidingly between said pins assaid door is opened and closed, said outstop arm being provided with ahooked end portion adapted to engage one of said locating pins when saiddoor is in its fully open position, said outstop arm being shaped sothat the distance between the top edge thereof to the upper pin is, inonly said broil position, greater than the distance said supporting armhooks must be raised in order to lift said hooks clear of said locatingpins when said outstop arm is raised upwardly and moved outwardly fromsaid oven;

whereby the engagement of said roller with said cam creates a valleytension point at said broil position; whereby the extent of verticaltranslational movement of said hook elements is limited to thesimultaneous vertical translational movement of said outstop arm;whereby said hinge can be removed from said oven only when the door isin its broil position by raising said door and said outstop armsufficiently high to permit said supporting arm hooks to be lifted clearof said locating pins and then sliding said outstop arm outwardly fromsaid oven; whereby said door can be returned to said oven by settingsaid outstop arm on said lower pin and moving, with said door slightlyelevated, said outstop arm inwardly between said pins until saidsupporting arm hook elements hook over said pins; and whereby thetension on said spring and the relative position of said supporting arm,said outstop arm, said cam, and said roller remains substantiallyconstant during such removal and return.

9. The hinge according to claim 8 wherein said tension link membercomprises a portion which is slidedly engaged in a longitudinal slot insaid door so that engagement of said roller with said cam, upon theclosing of said door, results in an outward radial movement of saidportion in said slot.

10. A hinge for the door of an oven for supporting said door at a fullyopen position, at a closed position, at a broil position intermediatethe doors. open and closed position, and at intermediate points, saidoven having structures fixed thereto for engaging elements of saidhinge; said hinge comprising:

(1) pivot means upon which said door pivots as it opens and closes;

(2) a link member provided with a cam follower, said cam follower beingmovably secured to said door for circular movement therewith and forradial movement with respect to said pivot means;

(3) a cam fixed relative to said pivot means, and, positioned to engagesaid cam follower at least when the door is adjacent to or at said broilposition and being then operable in a manner to effect radial movementof said cam follower;

(4) means for resiliently urging said cam follower in a radial directionopposite the direction effected by said earn;

(5) an outstop arm extending from and fixed to the inner side of saiddoor and adapted for sliding engagement with said oven structure whilesaid door is being moved from non-broil positions, where said ovenstructures obstruct the removal of said arm from said oven, to a broilposition, where said arm can be lifted free of said structures; and

(6) supporting hook means with a fixed position relative to said pivotmeans and said cam and adapted to removably engage said oven structures;

whereby said door and hinge can be removed from and returned to saidoven at only said broil position.

11. The hinge according to claim 10 wherein said cam follower is aroller.

12. A hinge for the door of an oven from supporting said door at thefully open position, at the closed position, at a broil positionintermediate the doors fully open and fully closed position and atintermediate positions, said oven having structures fixed thereto forengaging elements of said hinge; said hinge comprising:

(1) pivot means upon which said door pivots as it opens and closes;

(2) a link member provided with a cam follower, said cam follower beingmovably secured to said door for circular movement therewith, and forradial movement with respect to said pivot means;

(3) a tension spring cooperative with said door and said cam followervia said link member, said spring adapted to be under tension at allPositions of said door, said tension acting on said door in a directiontoward said doors closed position and in a direction to urge the camfollower radially relative to said pivot to control resiliently theposition of said cam follower;

(4) a cam fixed relative to said pivot means; and being positioned toengage said cam follower at least when the door is moving between thebroil position and the closed position, and when the door is in thebroil position; and

9 (5) supporting hook means with a fixed position relative to said pivotmeans and said cam adapted to engage said oven structures; whereby saiddoor may be moved from said open position to said broil position andback and may be moved from said lbroil position to said closed positionand back and is held releasably but stably in any of the open, theclosed or the lbl'Oil positions.

13. The hinge according to claim 12 wherein said cam follower is aroller.

References Cited UNITED STATES PATENTS 2,539,151 1/1951 Mills 126-1943,072,117 1/1963 Stoligrosz et a1. 126-191 3,299,879 1/ 1967 Doner126-194 KENNETH W. SPRAGUE, Primary Examiner.

